Is it a correct sentence?

No if's and but's please.

This is a good question. Lots of grammar nuts won't like it, but I'd say it's the best way to write it.

There is a lesson here on apostrophes used in plurals.

Lots of people claim that apostrophes should never be used in plurals. That's out of date. Apostrophes are useful for showing plurals in cases like yours. You won't find a grammar guide that doesn't condone it.